Freddie Oversteegen was born September 6, 1925, in the village of Schoten, Netherlands. Oversteegen was raised by her mother, who first taught her communist principles.

Freddie Oversteegen, her sister, and friend Hannie Schaft worked to sabotage the Nazi military presence in the Netherlands. They used dynamite to disable bridges and railroad tracks. They aided Jewish children by smuggling them out of the country or helping them escape concentration camps.

They were also good assassins and saboteurs. They also lured Nazis to the woods under the pretense of a romantic overture and then killed them.

Freddie and Truus were awarded the Mobilization War Cross by Dutch Prime Minister Mark Rutte for their acts of resistance during the war. There is also a street named after her in Haarlem.

She died on September 5, 2018, in a nursing home in Driehuis, one day before her ninety-third birthday.